Node to Node transaction with LMIC

Thanks a lot for the comments.

I adapted the LoRaMac-node (Semtech's) stack to our hardware for the P2P communication.
When running the ping-pong example I continuously face the TxTimeout problem. With oscilloscope I can see that periodically the DIO1 pin is triggered as well as the RXTX pin of sx1276. But the DIO0 and DIO2 are silent. In our realization of hardware the antenna switch is controlled by the sx1276's RXTX pin which seems to function well as it periodically jump to high level.

Could somewhat suggest what might be wrong or what can be checked to find the problem? One would expect that DIO0 and DIO2 to also go high at some point, but they don't.

Thanks a lot for any suggestion.